Air-brake system.



J. DILLANDBR. AIB. BRAKE SYSTEM. AYPLIGATION FILED SEPT. 23, 1908.

Patented Dec. 6, 1910y 5 SHEETS-SHEET l.

THE NaRRls PETA-Fs ca., wAsH'lNaruN, n. r:.

* J. DILLANDER.

AIR 'BRAKE SYSTEM.

. APPLIOATION FILED SEPT. 2s, 190s.

Patented Dec. 6,1910.

5 SHEETS-SHEET 2.

J. DILLANDEIL AIR BRAKE SYSTEM V. APPLICATION FILED SEPT. 23, 1908.

Patented Dec. 6, 1910.

' s SHEETS-emma.

.J. DILLANDER, AIR BRAKE SYSTEM.

A-PPLIOATION FILED SEPT. 23, 1908. 977,856.

5 SHEETS-SHEET 4.

Patented Dc.6,1910.

J. DILLANDER. AIB, BRAKE SYSTEM; APPLICATION FILED SEPT. 23, 1908.

Patented Dec. 6, 1910.

`TOI-IN DILLANDER, TEMPLE, TEXAS.

.AIR-BRAKE SYSTEM.

arnese.

To all 'whom it may concern:

Be it known that I, JOHN DILLANDER, a citizen of the United States,residing at Temple, in the county of Bell and State .of Texas, haveinvented a new and useful Air- Brake System, of which the following 1s aspecification.

This invention relates to air brake systems.

In the air brake systems in commercial use it is impossible to retainbraking pressure in the brake cylinder while the auxiliary reservoir isbeing recharged, so that aft-er one application of the brakes it isnecessary to release and then wait until the auxiliary reservoirs arerecharged before another application can be made. It is, furthermore,practically impossible to maintain a given pressure in the brakecylinder, and it is altogether impossible to graduate the pressure inthe brake cylinder and place the' pressure wholly under the control ofthe engineer.

It is the principal obj ect of the present invention to overcome theseobjectionable features and to provide a braking system that iscompletely and wholly under the control of the engineer, and by whichthe engineer may admit air to the brake cylinder under any desireddegree of pressure and maintain that pressure as long as he desires, orhe may increase or decrease the pressure and maintain the increased ordecreased pressure for any length of time, so that the train will bebrought under full control and may be stopped slowly or abruptly.

A further object of the invention is to provide a system that willpermit of the recharging of the auxiliary reservoirs while maintainingany given pressure in the cylinder, and, further, to permit of increaseor decrease in the braking pressure in the cylinder after an applicationof the brakes, and before the release of such brakes.

A still further object of the invention is to provide a duplex systemcombining both automatic and straight air features, and so arranged asto be operable independently of each other, or to a certain extentsimultaneously or successively, for the purpose of securing any desiredbraking effect.

A still further object of the invention is to provide a system that maybe used in connection with the ordinary train equipment of Westinghouseor New York air brakes, using either plain or quick action triples,

Specification of Letters Patent.

Application filed September 23, 1908.

Patented Dec. 6, 191i?.

serial No. 454,312.

and by which, said triples may be utilized as a part of a straight airsystem without in any manner detracting from or interfering with theirordinary use.

A still further object of the invention is to provide a system in whichafter the stoppage of a train it is unnecessary to wholly release thebrake cylinder pressure before starting, so that a portion of the airwill be retained in the brake cylinders at all times, and thus reducethe work of the pump.

A still further object of the invention is to provide a braking systemwhich may be operated with the utmost efficiency on a much lowerpressure than is now considered necessary, so that the work of the airpump will be materially reduced and the life of the air hose lengthened.

A still ,further object of the invention is to provide a novel form ofautomatic governor which may be placed on the engine for the purpose ofcontrolling the pressure of air admitted to the brake cylinder under thestraight air system.

A still further object of the invention is to provide for the employmentof two separate lines of train pipe one for the automatic brake and theother for the straight air, and to provide for the connection of thesevby a single coupling between the train so as not to increase the workof the train crew 1n connecting up.

With these and other objects in view, asf

will more fully hereinafter appear, the inventionconsists in certainnovel features of construction and arrangement of parts, hereinafterfully described, illustrated in the accompanying drawings, andparticularly pointed out in the appended claims, it being understoodthat various changes in the form, proportions, size and minor details ofthe structure may be made without departing from the spiritorsacrificing any of the advantages of the invention. Y

In the accompanying drawings z-Figure l is a view in the nature of adiagram* showing a duplex system constructed and arranged in accordancewith the invention, illustrating the manner in which ordinary plaintriples, Vestinghouse triples and New York triples may all be connectedin the same system, together with a novel form of triple valve, theconstruction of which forms the subject of a separate application forLetters-Patent. Fig. 2 is a detail sectional view of the improved formof triple valve illustrating the connections. Fig. 3 is a similar viewof the saine, showing the parts in the position assumed immediatelyafter the graduated or service reduction. Fig. 4 is a transversesectional view on the line 4-4 of Fig. 2, showing the retaining valve.Fig. 5 is a transverse sectional view of a slightly modified ar'angement of retaining valve to be used in connection with and appliedto the ordinary lVestinghouse or New York triple. Fig. 6 is a section onthe line 6 6 of Fig. 5. Fig. 7 is a detail sectional view oftheautomatic governor used in the engine cab. Fig. 8 is a plan view of thedial of the automatic governor. Fig. 9 is a sectional plan view on theline 9-9 of Fig. 7. Figs. 10 and 11 are views of hose couplings.V Fig.12 is a cross section of a portion of the hose coupling.

Similar numerals of reference arc employed to indicate correspondingparts throughout the several figures of the drawings.

Referring first to the construction of the triple valve, 10 indicates acasing provided with the usual auxiliary reservoir connec- -tion 1l andbrake cylinder connection 12,

and at the lower part of the main portion of the casing is a connection13 for the train pipe.

The main body of the casing is bored out to form a cylinder 14 whichcontains a bushing 15, and in this bushing is mounted the main piston16, the latter being arranged to uncover the feed groove 17 when in thefull release position shown in Fig. 2, so that air may iow through tothe auxiliary reservoir in the usual manner.

The rear portion of the casing is in the form of a cylinder 19 whichcontains a bushing 20. The lower portion of the bushing is grooved out,and faced to form a valve seat 21. In this valve seat are two ports 22and 23, the port 22 leading to the brake cylinder, and the port 23 tothe exhaust, or, in the present instance, to the retaining valveconnection. This valve, as will be hereinafter described, is employedfor the purpose of holding the pressurein the brake cylinder when thetriple valve is in full release position. It is, also, utilized for thepurpose of retaining within the cylu inder any predetermined pressure ofair, and for permitting alteration in the braking pressure.

The upper portion of the bushing 20 is provided with a dove-tailedgroove for the reception of a correspondingly shaped wedge block 25 thatis adapted to form a stop to prevent excessive inward movement of themain valve 27.

The valve 27 is in the form of a generally rectangular block, the upperface of which is inclined to correspond to the inclination of the lowerface of the wedge block 25,

and in the lower portion of this valve are three ports, 30, 31 and 32,the port 31 being in the form of a cavity through which the brakecylinder may exhaust to the port 23, while the ports 30 and 32 are incommunication with each other and are utilized in the operation of thedevice as hereinafter described. The larger port 32 opens at the bottomof the valve and the rear wall of said port is provided with a smallopening or port 33 through which auxiliary reservoir pressure may passon both service and emergency'reductions. The valve is further providedwith a longitudinal bore 35 which communicates through lateral ports 36wit-h the open space at the. sides of the valve. At the inner end of thebore is a tapered seat 37, and at the opposite or outer end the bore isenlarged, as indicated at 38, and terminates in a tapered seat 39 whichacts as a valve seat in several positions of the valve. Theoppositesides of the valve are further provided with short horizontalslots 40 for the passage of a transverse pin 41.

The rear side of the main piston is hol- --low and is bored out for thereception of an equalizing piston 42 that is free to slide within themain piston. The equalizing piston is, also, guided by a stem 43projecting rearward from the main piston, and having a tapered endportion that is arranged to engage against the tapered seat 37 at theinner end of the bore 35.

The equalizing piston 42 is provided with a hub 49 that projectsrearwardly in the direct-ion of the auxiliary reservoir and enters theenlarged portion 38 of the valve bore, but the diameter of the hub isless than the diameter of the enlarged portion 33, so that thecompressed air may freely pass between the two. At the point where thehub joins the equalizing piston, the base of such hub is tapered to forma valve 50 that is arranged to engage against the valve seat 39 andextending partly through the hub is a port 51 communicating at one endwith the space between the two pistons and opening at the opposite endat the extreme end of the hub.

The hub carries the pin 41, which, as before stated, extends through theshort slot 40, and the pin, also, passes through an elon gatedhorizontal slot 53 that is formed in the stem 43.

Vhen the parts are in the position shown in Fig. 2, train pipe pressureentering at 13 passes up through the passage 56 to the cylinder 14, andoperates on the main piston, tending' to thrust all of the parts to theright and retain the same in the position shown in Fig. 2. The air feedsthrough the leakage groove 17 and thence down the radial groove 57,passing through the casing on opposite sides of the valve to theauxiliary reservoir, and a portion of the air also Lpasses down betweenthe hub of the equalizing piston and the wall of the portion 38 of thebore to the groove l and into the space between the two pistons so thatthe latter becomes filled with air under auxil- 5 iary reservoirpressure. Y

To apply the brakes gently, or secure what is known as graduated orservice application, the engineer reduces the train pipe pressure byopening the engineers brake 'lo valve. The train pipe pressure beingweakened in the cylinder lf-l causes the auxiliary reservoir pressure tostart all of the parts moving to the left. The frictional resistance ofthe slide valve will cause pistons 16 and 42 to separate, as shown inFig. 3. The main piston continues its stroke and makes the full strokeagainst t-he packing ring 60. The parts are all carried to the left andport 32 is placed in communication with the port 22 leading to the brakecylinder, while the stem 43 opens the side ports 36, so that air mayiiow in through t-he side ports and the bore of the valve tothe port 32,and a small quantity of air will also enter through the port 25 33. Thisair passes to the brake cylinder and applies the brakes gently.

lt will be noted on reference to Fig. 2 that when the parts are in fullrelease position, the pin lil is at the outer or left hand end of theslot 40 of the valve and near the left hand end of the long slot 53 ofthe stem, so that as the equalizing piston moves to the left with themain piston, the pin will operate against the left hand end wall of theslots l0 and pull the valve over to the position shown in Fig. 3, whilethe elongated slot 53 permits traveling of the main piston to the limitof its stroke without working engagement between the end of the longslot and the pin.

lVhen the auxiliary reservoir air has passed into the brake cylinder tothe amount of the train pipe reduction, the engineers valve is placed inlap position and the weakened train pipe pressure forces the piston overVuntil the equalizing piston strikes against the rear wall of thecylinder. The valve then stands in what is known as lap position withall of the ports blank. In this position the space between the twopistons being lled with air under full auxiliary reservoir pressureprevents the main piston from moving to the right and consequentlyassuming release position. The air between the two pistons 'cannot nowescape forthe reason that the valve at the end of the hub has moved intocontact with the valve seat 39, so that the port 51 is closed. Theweakened train pipe pressure cannot compress the higher auxiliaryreservoir pressure between the two pistons, so that it is impossible tomove the pistons close together, and, therefore, movethe valve torelease position, this being accomplished only by raising the trainpipev pressure by placing the engineersbrake valve on full release or onrunning position. This feature of construction is of importance in thatit eliminates all auxiliary springs or stops, and at the same timepositively prevents accidental movement of the valve from lap to releaseposition.

Should the engineer wish to release the brake from lap position, he doesso in the usual way by increasing the train pipe pressure, and the partswill then assume the running position shown in Fig. 2, permittingrecharging of the auxiliary reservoir in the usual manner.

If the engineer wishes to apply the brak-es in emergency, a very quickand heavy train pipe reduction is made by proper movement of theengineers brake valve. The train pipe pressure is suddenly weakened inthe cylinder 14, and the high auxiliary reserg5 voir pressure suddenlyacts on the main and equalizing pistons, forcing both of them to theleft, the main piston making its full stroke as before. The reduction intrain pipe pressure is so great and the movement of the piston is soquick that there is no opportunity for the escape of the high pressureair from the space between the two pistons, and both pistons will moveas a unit and the valve will be carried back a. much greater distancethan in the graduated or service reduction in order to allow the air toflow from the train pipe through passage 56 to the cylinder lt, thencethrough passage 70 to the port 30 and port 32 to port 22 and brakecylinder. As soon as the auxiliary reservoir pressure can feed throughthe small port 33 and reduce below the high pressure in the spacebetween the two pistons, this body of air under pressure will force theequalizing piston to the right, moving the slide valve in such manner asto cut olf the port 70 and stop the further flow of air from the trainpipe, while allowing the auxiliary reservoir pressure to continue toflow through the ports 36, bore 35, and port 32 to the brake cylinder.

It will be noticed that this operation is accomplished, that is to say,the reduction of train pipe pressure to quicken the action of the nextbrake, and the application of the auxiliary reservoir air in bothgraduated and emergency applications, also, the equalizing of the trainpipe pressure with the brake cylinder, by means of the single slidevalve, there being no auxiliary valve either slide or check, and nostopping or cushioning springs or other devices to limit the movement ofthe parts.

At one side of the main valve casing, and preferably formed integraltherewith is a cylinder 8() having a bushing 8l in which is mounted apiston 82. rlhe upper end of the casing communicates through a lateralport S4 with a pipe 85 leading to the engine, and 133 CFI through whichair under any predetermined pressure may be forced. small strainer 80 ispreferably introduced at the top of the bushing to prevent the entranceof dil't, and at the side of the bushing is formed a small leakagegroove 87. The lower end ot the cylinder communicates with the port 23constituting the exhaust ot' the triple valve, so that the piston 82will be raised by the pressure otl air escaping from the brake cylinder,and will be forced downward by the pressure of air entering through thepipe 85, as well as by its own weight.

The lower end ot the cylinder is threaded and receives a plug 90. rllhisplug is centrally bored and provided with a bushing 91 in which isformed a tapered valve seat 02 t'or the reception ot al valve stem 98that is carried by the piston 82. The bore ot' the bushing communicateswith the interior of the cylinder .through lateral ports 94.

It there is no pressure in the pipe 85, the exhaust passing from thebrake cylinder to the port 23 will raise the piston 82 -and the air willescape through the ports 94 and the bore ot' the plug 90 to the outerair, thus releasing the brakes, but if the engineerl wishes to retainthe brake cylinder pressure he forces air through the pipe 85 so as tohold the piston down and thus prevent the escape of air from the brakecylinder even after the triple valve has been moved to release position.This is of importance in that it permits the holding of the brakingpressure while the auxiliary7 reservoir is being recharged in theordinary manner, although it requires an extra pipe 85 leadingthroughout the train and provided with suitable means under the cont-rolet the engineer for connecting it to a suitable source of air supply.

Should the engineer wish to increase the pressure in the brake cylinderover and beyond the initial braking pressure he may torce air under highpressure through the pipe 85 and this air will keep the piston 82 downand will feed through the groove 87 into the lower portion ot thecylinder, and thence through the port 28, the port 31 of the slidevalve, and down through the port 22 to the brake cylinder, so that, ifdesired, pressure may be maintained in the brake cylinder for any periodof time, and the operation will be wholly independent of the automaticbraking system, while the pressure of the lattermay be held in reservewith the auxiliary reservoir charged and ready for use. Provision is,also, made for slightly reducing the pressure in pipe 85 in case thebraking power is in excess oi. that required, so that the air passingfrom the brake cylinder will slightly raise the piston 82 and partlyopen the valve to permit the escape of a portion of the pressure withinthe brake cylinder.

The construction just described, and as shown in Fig. 4, is used wherethe improved lorm otl triple is employed, but where the ordinary`Westinghouse or New York triple valves are to be employed in the samesystem, a slightly diiterent construction shown in Figs. 5and 6 isadopted. In this case the retainer is made in the form of a separatemember which may be attached in the auxiliary straight air pipe 85 andconnected to the port ot' the triple valve. The casing 100 of themodified construction of retainer is approximately in the form of aT-joint, which may be coupled into the pipe 85 and at the opposite sidesof the lower portion of the casing are threaded openings 101, either ofwhich may be connected by a short pipe 102 to the exhaust portof theordinary triple valve, while the opposite opening is closed by a plug108. This permits of the application of the retainer to either side ofthe triple valve and facilitates connection of the parts. The operation,however, is precisely the saine as previously described.

The automatic governor which is placed in the cab of the engine isentirely independent of the engineers brake valve, and may be operatedindependently or in conjunction with said valve. connection between themain reservoir or other suitable source of air pressure suppl-y and thepipe 85 and its construct-ion is such as to automatically regulate thepressure sent through the pipe 85 to the brake cylinder, it beingpossible for the engineer by setting the governor to retain anydesired'pressure in the cylinders.

The main casing 105 is connected at 106 to the main reservoir on thelocomotive, and at 107 is connected to the straight air pipe 85. At thelower right hand side of the casing is a cylinder 108 having abushing109 in which .tits a piston 110. The cylinder also contains abushing 111 in which slides apiston 112, the two pistons 110 and 112being permanently connected together by a stem 113 which carries a valve114 controlling a port 115. The air entering at 106 from the mainreservoir operates on both pistons, but

as the piston 110 is of much greater area than the piston 112, the twopistons will be carried to the left and the valve 114 will be moved toopen position, allowing the air to flow through the port 115 from whenceit passes in a rather indirect path to a port 117 and thence through theconnection 107 to the straight air pipe 85. The outer end of thecylinder 108 is closed by a plug 118 and ports 120 are provided'throughthe plug for the purpose of allowing the free flow of atmospheric airinto and from the outer end of the cylinder, so that the outer face ofthe small piston 112 is exposed only to the normal or atmosphericpressure.

At the lett hand sidefof the main casing is a cylinder 122 containing aperforated bush- Its function is to controll ing 123, and at theopposite end portions of the bushing are valve seats 124 and 128 whichare engaged by a pair of check valves 126 and 127, said valves beingnormally pressed in the directions of their seats by a pair otlcompression springs 180. The resistance of these springs must beovercome by the air pressure passing from port 117 to the pipe 85, andthis may be readily accomplished, the spring being a comparatively lightone, so that air may be allowed to flow from the automatic governor tosaid pipe 85. At the extreme outer end of the cylinder 122 is arranged asmall casing 134 having an exhaust port 135, and the opposite end of thecasing has a threaded nipple which screws into the threaded end ot' thecylinder 122 and serves partly as a means for holding the bushing 123 inposition within the cylinder, while the seat 124 is formed on an annularflange extending inward from the wall of the casing.

The lower portion of the wall of casing 134 has a threaded opening forthe reception of a plug 140 that is provided with a central recess forthe reception of the lower end of a cylindrical stem 141 that passes upthrough an opening formed in the casing and is provided with a suitableoperating handle 142. This stem is provided with a i-lange or collar 144that is forced against a packing ring 145by means of a coiledcompression spring 146 seated in a recess at the bottom of the stem,this construction serving partly for the purpose of preventing leakage.

The stem 141 is partly cut away at one side to form a flat face. Thisfla-t face of the stem is arranged to engage a valve operating rod 149carried by the valve 126 and by turning the stem, the flat tace of thelatter may be forced against the end of the rod, thereby moving thelatter in the direction of its length and opening the valve slightly forthe purpose of allowing pressure to eX- haust from the straight air pipe85 through to the main exhaust port 135.

In the upper central portion of the casing 105 is a cylindrical chambercontaining two bushings 150 and 151 between which is clamped the outeredge of a yieldable diaphragm 152. This diaphragm is carried by a twopart piston 153, the upper section of which is guided within the bushing150, while the lower section is guided within the bushing 151, and thetwo parts of the piston are permanent-ly secured together by a nut. 154.The top of the upper section of the piston 158 is recessed to receivethe lower end of a spring 155, the upper end oi said spring being housedin a recess formed in the lower face of a vertically movable nut 156that is guided in an opening formed in the reduced neck of the uppersection 157 of the cylinder.

The periphery of the neck is threaded for the reception of a cap piece159 which may be screwed down into place and locked by a nut 160.

The central portion of the cap v159 is provided with an opening for thepassage of a stem 162, the lower portion of which has a quick pitchscrew thread 162 fitting the threads of the nut 156. Near the upperportion of the stem is an enlarged flange 165 that bears against theinner tace of the cap and receives the thrust of the nut, and the spring155. Y

To the extreme upper end of the stem 162 is secured an operating handle166 having a detent 167 which may be readily shifted, and allowed toremain in any one of a series of shallow depressions 168 that are formedin an indicating disk 169 adjustably secured to the top of the cap.

The disk is provided with a series of depressions 168 and opposite eachis a mark indicating the pressure sent from the main reservoir throughpipe 85 to the brake cylinder. In the present instance any pressure fromten pounds to two hundred may be thus transmitted. The indicating diskis provided with two long arcuate slots 170 for the passage of a pair ofsecuring screws 171. This is for the purpose of permitting adjustment ofthe indicating disk to the Zero point of the spring, and is ofconsiderable importance in that it thereby avoids the necessity ofemploying springs of precisely the same length and capacity. In otherwords, it is merely necessary to introduce a spring of approximately theright length and strength and then turn the handle 166 until the springbegins to resist further movement of the nut,156. The indicating disk isthen turned until the zero mark is under the handle and said disk isthen locked in place. This construction provides also for suchadjustment as may be necessary to compensate for fatigue in the spring.

Arranged in axial alinement with and below the diaphragm 152 is achamber 173, the lower end of which is closed by a plug 174. At the topof the chamber is a bushing 175 through which extends a port 176, incommunication with the port 117, and at the base of the bushing is aseat for a valve 178 that is carried by a vertically movable stem 179normally forced upward by a spring 180. The upper end of the valve stemis arranged immediately below the nut 154, and on downward movement ofthe latter the valve will be forced away from its seat so as to placethe chamber 17 3 in communication with the port 117.

The chamber 173 is in communication with the left hand end of thecylinder 109 through a small port 182 and this end of the cylinder is incommunication with the second portion of said cylinder through a smallport 183, so that under all circumstances the main reservoir pressuremay How through the port 183 and 182 to the left hand end of thecylinder, and the chamber 173 and as the area of the piston 110 exposedto pressure at the leit hand end oi' the cylinder is greater thanthearea exposed to pressure at the opposite side, the piston will always bemoved to position to maintain the valve 11st in closed position.

It' the engineer desires to send twenty pounds pressure to the diiierentbrakecylinders, he turns the handle 166 until it 1s opposite theindicating mark 20 on the disk. This forces down thenut 15G and themovement is transmitted through the spring 155 tothe piston anddiaphragm, forcing the latter downward and nut 151 engages the stem 179of the valve 17S, thereby forcing the latterto open position andallowing the air to exhaust from the left hand end or' the cylinder 109through the port 182 to chamber 173, and port 176 to port 117, openingthe check valve 127 and passingthrough the connection 107 to the pipe85. The superior pressure from the main reservoir then actingon theright hand face of the piston 110 will force the latter to the lett,moving the valve 11-1 to open position and allowing free passage ot themain reservoir air through the port 115 and port 117 to the connectionS5, the pressure being reduced at the check valve 127. The tlowcontinues until the whole of the pipe and all of the brake cylindershave been filled with air under twenty pounds pressure, and then thissame pressure. acting below the piston 153 will counter-balance theaction ot the spring 155 and compress the same to the extent of twentypounds, thereby raising the piston and the nuty 143-1; clear of theupper end of the stem 179, so that the valve 17S is free to close andprevent further passage et air from the left hand end of the cylinder109. rlhe main reservoir pressure will then continue to flow through theports 183 and 182 until the pressure at the left of the piston 110 issutlicicnt to force it back to the closed position and the parts willthen reassume normal position, while retaining twenty pounds pressure inthe straight air pipe S5 and in the brake cylinder. Should the engineerdesire to increase this pressure he moves the handle 100 to the desiredpoint, for instance, until it is opposite the thirty, forty, titty, orother mark, and thus forces the piston and diaphragm 152 downward untilthe valve 17S is again moved to open position and-the same operationtakes place until the back pressure in the straight air pipe equals theresistance oiieredy by the spring and moves the spring upward forthepurpose ot' permitting closing movement of the valve 178. In eitherinstance the reduction of pressure at the brake cylinder or cylindersthrough any leakage in the train pipes will reduce the pressure that Visacting to compress the spring 155, and the spring in expanding willagain open the valve 17S, so that sutlicient air will pass through fromthe main reservoir to supply that lost by leakage, so that this pressuremay be maintained in the brake cylinders automatically and withoutregard to any leakage at the hose or other connections.

lVith a construction of this kind it is possible for the engineer intraveling down grade to maintain any desired degree of pressure in thebrake cylinder independently ot the automatic brake, andV it the motionof the train is not checked quickly enough he may increase the pressure,or if 'the stoppage is too abrupt he may release the pressure by turningthe handle 1112. iside from this, when the train has been brought to afull stop, it is not absolutely necessary to empty the brake cylinderbefore starting a second time. By manipulating the handle 142, thepressure in the several cylinders may be gradually reduced until thetrain starts and some pressure may still be maintained in the brakecylinders so that all of the air is not lost and work of the pump is`thus materially reduced. t is possible, furthermore, to secure adequatebraking effect by long continued application of air under comparativelyslight pressure without the necessity ot carrying the .extremely highpressure, such as is now considered necessary on passenger service,these high pressures being. very dangerous owing to the liabilityof'bursting of the hose connections and consequent application of thebrakes while the train is running at full speed.

ln general practice, it is usually found desirable to make either aservice or emergency application by means of the automatic brakingmechanism and after this has been made and the movement of the trainpartially checked, the automatic governor is set to retain the pressurewhich the engineer desires to hold inthe brake cylinders. The engineermay then move the usual engineers brake valve to release or runningposition and bring the triple valve to such position as to exhaust thebrake cylinder. ln exhausting, however, the air will pass under thepiston of the retaining valve and will tend to raise the same, but willmeet the pressure previously vsent through the pipe 85 and which is thenacting on the upper side o1 the piston of the retaining valve. It thebrake cylinder pressure is superior the piston will be raised and brakecylinder air will escape to the atmosphere until the pressures arebalanced. while the pressure in the brake cylinder will then remainexactly that which was sent by the engineer through the pipe 85, orifthe engineer wishes to maint-ain a braking pressure greater than thatwhich was in the brake cylinders, this greater pressure operating on topof the pistons of the retaining valve Will hold the same down and thepressure will feed through the leakage ports around said pistons andenter the brake cylinder in the manner previously described in order toincrease the brake cylinder pressure to the required point.

In order to avoid the necessity of providing separate couplings for themain train pipe and the additional straight air pipe employed in thissystem, a duplex coupling is used, and this coupling is ot suchconstruction that both pipes may be coupled at the same time or it maybe utilized in connection With the ordinary single train hose couplingnow in ordinary use.

Each coupling comprises a casting 200 having a pair of terminal ports201 and 202 which are entirely independent of each other and are incommunication with the auxiliary straight air hose 85 and the train pipehose 204k, and at each port are arranged the usual yieldable gaskets Q05in order to prevent leakage. At a point adjacent the port Q02 thecasting is provided With a Wing 206 and an arm 207, the latter beingarranged to receive the Wing 206 of a mating coupling member so that atthis point connection may be made With the ordinary Y train pipe hose incase the train is made up of cars having the ordinary equipment andother cars having the improved equipment. In addition to these couplingmembers, a tongue Q10 projects upivard from each of the members 207 andarranged adjacent the port 202 are oppositcly directed platesl 211, Q12,the plate 212 et one coupling being aranged to enter bet-Ween the tongue210 and plate Q11 of the opposite member, so that both couplings may beconnected at a single movement, and the Work of the train crew Will notbe increased by the addition of the straight air pipe.

The engineers valve herein .shown and described forms the subject matterof another application Serial No. 454,314: filed by me on September 23,1908, and the triple valve herein shown forms, in part, the subjectmatter of Letters Patent No. 930,640 granted August 10, 1000 on anapplication tiled by me.

Vhat is claimed is l. In combination with automatic air brakes, astraight air train pipe connected with the exhaust ports of the triplevalves of the automatic air brake system, an ad justable pressuredetermining valve for charging the straight air train pipe, and amanually operable valve at all times accessible to the engineer foropening the saidv train pipe to the atmosphere at will.

2. The combination with an automatic air brake system., of a straightair train pipe connected to the exhaust ports of the triple valves ofthe automatic air brake system, and a regulating valve and an exhaustvalve for the straight air pipe both at all times accessible to andmanually operable by the engineer. j

The combination with an automatic air brake system, of a straight airtrain pipe connected to the exhaust ports of the triple valves of theautomatic air brake system, a. free valve betweenthe exhaust port ofeach triple valve and the straight air train pipe movable by exhaustpressure from the triple valve to open the exhaust'port of said triplevalve to the atmosphere and by pressure in the straight air pipe toclose the atmospheric connection and in the last named position openingthe straight air train pipe to the brake cylinder through the exhaustport of the triple valve, a pressure determining valve for the straightair train pipe at all times under the control of the engineer, and anexhaustva ie for the straight air train pipe also at all times under thecontrol oi' the engineer.

In testimony that I claim the foregoing as my own, I have hereto aiiixedmy signature in the presence of two Witnesses.

JOHN DILLANDER.

Iitnesses CHAs. C. JONES, F. L. DENIsoN.

